In parts 1 and 2 of this series, we talked about the two custom chips in the Amiga which contributed to the graphical excellence of the platform compared to its competitors. In this part, we will talk a bit about how the third and final chip, Paula, lead to the invention of an entirely new audio representation format – the tracker module – and what this meant for audio in games. Tracker software still exists today, and is heavily used in the techno music scene . While it isn’t used so much in video games now, outside of handhelds, the early Unreal engine supported a kind of tracker format for in-game music until about 2000 or so (the games Unreal, Unreal Tournament and Deus Ex all had their memorable sound tracks composed in this format, and all hold up today).
At the time the Amiga 1000 launched, almost all home computers generated audio via internal synthesizers – essentially, simple chips capable of generating simple sound types like square, sine and triangle waves, and combining multiple signals into a more complex sound. The modern music form called “chiptune” is the survival of the kind of musical techniques capable with this kind of technology.
With the Paula custom chip, however, the Amiga supported sample based audio. Instead of generating sound by adding together primitive signals, sample based audio uses recordings of real sounds as a basis for audio, playing them back either at their original pitch, or shifted to different notes. Paula was capable of playing up to 4 samples at once, two in the left channel and two in the right for stereo sound, but could change which samples it used during playback, freely.
In order to manage this newly available audio type, Amiga programmers developed a new type of audio programming tool, a “tracker”, which could be used to orchestrate the samples used and the sequence of notes to play with them. The resulting collection of samples and orchestration was saved as a “module” file, taking up a bit more space than synthesizer-based formats (because of the included samples), but still significantly less space than a full recording of an audio performance.
Tracker-based music allowed surprisingly high quality music to be provided with almost all Amiga games (and also filtered rapidly into other avenues, like the demoscene). Almost all of my abiding memories of Amiga games are related to their music and soundscapes, from the achingly sad piano in the Agony soundtrack, through Sensible Software’s ska-based track to Cannon Fodder, Zool’s rock’n’roll intro, and Gods’ intro “Into The Wonderful”
But more than just video games, the “community” nature of home computers in the 80s and early 90s meant that tracker music was often distributed on coverdisks (of which more later) as artistic pieces. Because tracker software was often public domain or shareware, you could play these musical pieces (for example, these tracks compiled here) in the tracker itself – I have strong memories of watching the sample tracks sweep by, and constructing my own (terrible, of course) tracks from samples ganked from these coverdisk compositions. The experience of being able to watch the actual composition being interpreted as I watched was something that deeply resonated with me, and I think contributed to a deeper sense that anything a computer did wasn’t magic, but the result of understandable, if complex, processes.
Paula was the only of the three custom chips in the Amiga never to be replaced with an upgraded version in later models. Even by 1990, the newly released Super Nintendo still couldn’t reliably match the old Amiga sound chip (thanks mainly to memory limitations), as this side by side comparison demonstrates: https://www.youtube.com/watch?v=s2kAPcMDExE